Question

A sound wave is incident on a poolof
fresh water. The sound enters the water perpendicularly andtravels
a distance of 0.51 m beforestriking a 0.24-m-thick copper
blocklying on the bottom. The sound passes through the block,
reflectsfrom the bottom surface of the block, and returns to the
top of thewater along the same path. How much time elapses between
when thesound enters and leaves the water?
s